You're putting up lame strawmen. No one claimed "Engineering = success".
The claim is that it is absolutely impossible to have a tech startup without engineers, and no idea, no matter how cunning it might be, can have success if engineering can't turn it to into reality.
A tech startup without engineering is snake oil. Simple as that. Let's not pretend that a salesperson parachuting into a startup with a product in the market can possibly have a comparable impact to those who actually deliver the actual product.
You can build a fairly successful startup with little to no engineering.
Sure, engineers are usually pretty important (they're great at automating tasks to improve efficeincy)... but so are many other roles.
Best engineers making the best product ever will not make a dollar without good sales people and marketing and product managers and VC and ... You need ALL of these to make a succesful company.
I think it's especially hard to appreciate sales+marketing since they seem so ephemeral while tech is concrete. Sadly there also also too many examples of marketing getting too far ahead of the product, over promising, or devaluing engineering.
Best is definitely a balance, where all sides respect others' work and can see both the effort and its benefits.